Israel's Defence Minister Ehud Barak (l.) sits across from Prime Minister Benjamin Netanyahu (2nd r.) during the weekly cabinet meeting in Jerusalem on Sunday. Netanyahu dropped heavy hints on Sunday of an early election, shifting the national focus from a former spymaster's accusations that he could start a 'messianic' war with Iran.

When Gen. Martin Dempsey, the chairman of the US joint chiefs of staff, said in February that it wouldn't be "wise" for Israel to attack Iran and said that the "Iranian regime is a rational actor" that can be negotiated with and pressured via sanctions, he received a withering attack from the hawkish American right and criticism from Prime Minister Benjamin Netanyahu's government.

The Israeli newspaper Haaretzreported then that Mr. Netanyahu and Defense Minister Ehud Barak told US officials privately that General Dempsey's comments "served Iran's interests" and that an unnamed senior Israeli official complained "the Iranians see there's controversy between the United States and Israel, and that the Americans object to a military act. That reduces the pressure on them."

Well, now Dempsey has been joined by a number of other security experts who appear to share his point of view on a unilateral Israeli attack on Iran. They are Meir Dagan, the former head of the Mossad, Israel's international spy service; Yuval Diskin, the former head of the Shin Bet, the country's domestic intelligence service; (Ret.) Gen. Gabi Askhenazi, a former head of the Israeli Defense Forces (IDF); and Gen. Benny Gantz, the current head of the IDF.

Showing how raw emotions are, and how split the Israeli establishment is on war with Iran and other issues, former premier Ehud Olmert spoke out against a rush to war with Iran in a speech in New York sponsored by The Jerusalem Post on Sunday. According to the New York Times, Mr. Olmert cautioned against war with Iran, said Netanyahu was disinterested in making the compromises required for peace with the Palestinians, and warned Israel against alienating the Obama Administration. Of Obama, Olmert said: "You have to respect him.... He is the president of the most powerful nation on Earth, and happens to be a friend of Israel."

That comment drew boos from the largely Jewish-American crowd, and at other moments audience members shouted out "Neville Chamberlain" (the UK prime minister who sought to make peace with Hitler) and "naive."

Israel is turning towards elections that must be held by the end of next year, but that many in the country now speculate will be moved up to this fall, ahead of the US presidential election. At the moment, Mr. Netanyahu and his coalition partners look well positioned to retain the government, but the public squabbling can't be helping.

Israeli politicians are known for their very public disagreements, but differences between security officials past and present and Israel's sitting government – especially on a topic as critical as this – are rare. Israel's generals have far more sway over policy in Israel than US ones do, at least historically, and in the case of the war posturing over Iran's nuclear program the simple message of their public comments appears to be: Don't.

But the debate is also a sign of how much Israel's political culture is changing. Allies of Netanyahu have been whispering that Mr. Diskin and Mr. Dagan are merely angry that they didn't retain senior posts and are lashing out in a fit of pique.

More generally, Israel's political order has been transformed in recent decades. The views of men like Netanyahu were once to the far right of Israeli public opinion. They are now firmly in the center, and the centrist and cautious views of many in the older cadre of senior officers have shifted from the center, to what might now be called the left.

Diskin's comments were the most striking, even shocking. A career internal security man, much of his climb through the ranks was in dealing with terrorist attacks emanating from the West Bank. He declared both Netanyahu and Mr. Barak unfit to lead Israel, accused them of "misleading the public on the Iran issue," and said that contrary to their position that military action would deter Iran "many experts say that an Israeli attack would accelerate the Iranian nuclear race."

"My major problem is that I have no faith in the current leadership, which must lead us in an event on the scale of war with Iran or a regional war. I don't believe in either the prime minister or the defense minister. I don't believe in a leadership that makes decisions based on messianic feelings," Diskin told a political meeting. "Believe me, I have observed them from up close.... They are not people who I, on a personal level, trust to lead Israel to an event on that scale and carry it off. These are not people who I would want to have holding the wheel in such an event."

Haaretz columnist Anshel Pfeffer said Diskin's warning that an Israeli strike could harden an Iranian desire for the bomb is striking. "While it is true that many experts have expressed this opinion, this is the first time that a central figure who was so recently within the innermost security circles has said such a thing."

The logic of Diskin's point is simple. Though Iran insists publicly that it doesn't want a bomb, it can see the example of the NATO bombing campaign that helped drive Libya's Qaddafi from power (a few years after he gave up his nuclear program) on the one hand, and the freedom from external military interference of North Korea on the other. Israel's war planners believe a successful strike on Iran could knock its nuclear efforts back a few years, but not wipe it out entirely. Perhaps it will reason in the aftermath of such a strike that the best way to guarantee its security is to get the bomb, after all.

General Gantz said last week that he deems Iran rational, and that though he's deeply concerned that Iran is advancing towards the place where it could get a bomb, if it so chose, that it isn't committed to taking the final step yet. He said:

"If the supreme religious leader Ayatollah Ali Khamenei wants, he will advance it to the acquisition of a nuclear bomb, but the decision must first be taken. It will happen if Khamenei judges that he is invulnerable to a response. I believe he would be making an enormous mistake, and I don't think he will want to go the extra mile. I think the Iranian leadership is composed of very rational people. But I agree that such a capability, in the hands of Islamic fundamentalists who at particular moments could make different calculations, is dangerous."

This is a very different position from that of Netanyahu and Barak, who have insisted repeatedly that the time for action is nearly at hand, and that negotiations will go nowhere.

Environmental Protection Minister Gilad Erdan, a member of Netanyahu's Likud, and Dagan also went at in in New York over the weekend. Dagan said he agreed with Diskin's position, to which Mr. Erdan responded that Diskin was simply bitter he'd been passed over for a senior position. To that, Dagan responded, "You're a liar." Erdan also said that "Mossad chiefs [shouldn't] sabotage Netanyahu's efforts to garner the world's support against Iran."

What to make of it all? Simply, that there are major splits within Israel on the right course of action going forward. A healthy debate is being had on that question, right out in the open.